Ministers risk “messing up” plans for a 5p charge on plastic bags by making it too complicated.

Last September the Deputy Prime Minister announced the mandatory charge for single-use plastic carrier bags in England from Autumn 2015.

But MPs on the Environmental Audit Committee fear plans to exempts biodegradable bags and corner shops from the charge could be counterproductive.

They want Defra to follow the blanket ban approach in Wales which led to a big drop in bag use of 76%. In a report released today the MPs claim exemptions would make it confusing for consumers and potentially harmful for the recycling industry.

Joan Walley MP, Chair of the Committee said: “Biodegradable bags are not as green as they first sound. We heard that they can do as much harm to wildlife as normal plastic bags and could cause big problems for the UK recycling industry, which would have trouble separating and processing the different material.”

She added: “Before the Government reaches the check-out with this policy, it needs to drop the exemptions and keep it simple to help shoppers do the right thing.”

More than 8 billion disposable carrier bags are used in England each year – that’s around 130 bags per person a year. In contrast, people in Wales now use just 22 a year after the introduction of a 5p charge.